Questions about LibP2P (specifically for usage in Flow)

[vishalchangraniaxiom-old]

Hi,

I am engineer working on Flow (https://www.withflow.org/en/). We were considering using LibP2P as our underlying transport library and had some questions around that. If you don't mind, can you take a look at it and we will also join your call on Monday?
Thanks in advance.

Technical questions -

1. Is there a hard limit on the message size for the pub-sub communication? Can we change that? (Will pubsub: Message is unsized specs#118 be fixed?)
2. Apart from the pubsub model of communication, we also need a 1→K form of communication where one node requests K other nodes for information and each of the K nodes replies independently using a direct 1-1 communication to the requesting node. K is a subset of N, the total number of nodes. I don't think this can be implemented using the pub-sub model since there are no topics which are known beforehand. Hence, to realize this on top of libp2p, each node in the network could implement a random deterministic function to select k nodes (where k is a subset of K). The node then talks to these k nodes directly (1-1) which in turn, in addition to replying to requesting node, also choose their own k nodes from the K (where K is sent as part of the message metadata). I had the following question w.r.t this approach -
   1. Will a node reuse its Peer connections (fanout or mesh connections or gossipsub connections)?
   2. Will the messages thus exchanged be added to the message cache implicitly?
3. Is there a way by which a new node that just joined can ask for all the messages it has missed for a particular topic? I understand that the gossipsub will provide those to the node eventually using the IHAVE and IWANT exchanges but I am concerned about the delay in getting the node populated with all the messages it has missed with that approach.
4. Can you provide me with a working example of the pubsub communication in Go?

Non-Technical questions -

1. How many active contributors does the libp2p go project has?
2. What is the process of raising an issue or requesting a code change?
3. Do you accept Pull requests?

thanks,
Vishal
Scalability Engineer,
Dapperlabs